A gas turbine engine generally includes a fan and a core arranged in flow communication with one another. Additionally, the core of the gas turbine engine general includes, in serial flow order, a compressor section, a combustion section, a turbine section, and an exhaust section. In operation, air is provided from the fan to an inlet of the compressor section where one or more axial compressors progressively compress the air until it reaches the combustion section. Fuel is mixed with the compressed air and burned within the combustion section to provide combustion gases. The combustion gases are routed from the combustion section to the turbine section. The flow of combustion gases through the turbine section drives the turbine section and is then routed through the exhaust section, e.g., to atmosphere.
It is often desirable to route compressed air from one section of the engine to another. For example, a cooled cooling air (CCA) heat exchanger system may be used to cool compressed air bled off the compressor section of the engine prior to providing the cooled, compressed air to cool other engine components. Piping systems used to route such air may experience temperature gradients that cause thermal growth mismatches between sections of pipe. To reduce thermally induced stresses between the pipe sections and ensure proper system operation, slip joints may be used to allow adjacent sections of pipe to move relative to each other.
Conventional slip joints in pressurized piping systems experience thrust loads between the pipes that they join. In general, a larger pipe diameter at the slip joint results in a greater surface area for the fluid pressure to act on and thus a greater resulting thrust load. Reducing the slip joint diameter reduces the resultant thrust load, but smaller diameter pipes can also constrict the flow and cause an undesirable pressure drop.
Certain piping systems accommodate thermal expansion and thrust loads between sections of pipe by using larger slip joints or by using different types of joints such as bellows expansion joints. Alternatively, slip joints may be avoided altogether by routing a single pipe such that it is allowed to bend or flex. However, all these options are larger, heavier, and/or cause greater blockage to a fluid flowing around the piping system.
Accordingly, a piping system with features for improved accommodation of thermal growth would be useful. More specifically, a slip joint assembly that accommodates thermal growth and reduces thrust loads within a piping system would be particularly beneficial.